Solidified normally liquid hydrocarbons



Patented d. 2, 1945 ulql LY mo 4 Rocnons No Drawing. Application March 18, 1942, Serial No. 435,18?

6 illaims.

This invention relates to new and useful improvements in solidified normally liquid hydrocarbons.

The normally liquid hydrocarbons in accordance with the invention are of the inflammable type and are preferably of the combustible fuel type. One example is, for instance, a petroleum distillate. Another example is a mixtureof hydrocarbons of the benzene series. Although such normally liquid hydrocarbons as are used for fuel ordinarily contain numerous hydrocarbons, the term hydrocarbons as usedherein includes the limiting case in which only one hydrocarbon is present. As a normally liquid hydrocarbon I may, for instance, use gasoline, although I prefer a petroleum distillate of closer boiling point. Also benzcl or a light coal tar distillate consisting predominantly of benzol homologues may be used. The normally liquid hydrocarbons in accordance with my invention are preferably for ordinary use readily inflammable and preferentially then possess a dash point not substantially above normal temperature so that combustion may be started by means of a match or similar lighter while the fuel is at normal temperature.

One method of solidifying normally liquid hydrocarbons comprises the formation in situ in the hydrocarbon to be solidified of a voluminous gel of a metallic soap substantially insoluble or limitedly soluble in said hydrocarbon. This is accomplished by reacting a hydrocarbon solution of a. suitable organic compound, saponifiable to yield a voluminous metallic soap, with a suitable saponification agent suspended in the hydrocarbon solution in substantially dry pulverulent form, and permitting the reaction to proceed in at least the last stages thereof while the reaction mix is in substantially quiescent condition.

The saponification reaction is preferably one of acid neutralization. The suspension of saponification agent must be maintained substantially stable during at least the quiescent stage of the reaction, i. e., no appreciable segregation of suspended particles should occur upon discontinuance of agitation. This may be accomplished by the formation of a portion of the soap gel to a point at which the viscosity imparted to the mix by the gel is sufiicient to substantially maintain the particles in suspensionwhile the mix is quiescent and in the limiting case by a suspension of particles of saponification agent of such fineness that the same remain suspended substantially without presence of soap gel. In any case, however, viscosity of the mix and particle size of saponification agent must be so coordinated at the beginning of the quiescent reaction stage that no appreciable segregation of particles of saponification agent occur during that stage. Except in the limiting case referred to, agitation of the mix should be resorted to until the desired point i perature until gel formation has proceeded to a point at which the desired viscosity is obtained. Heating and agitation may then be discontinued and. the reaction will proceed while the mix is substantially quiescent at a more or less rapid pace. Completion of the solidification while the mix is substantially quiescent is of importance as disturbance by agitation during at least the last stages of congelation is detrimental to the desired characteristics and particularly to the homogeneity of the solidified product.

In certain instances the saponification reaction proceeds only with difiiculty atlower temperatures. This is particularly true with somewhat larger particle sizes of the suspended saponification agent. Furthermore, in certain instances, particularly when using rosin, the temperature required in a satisfactory saponification reaction is relatively high and in many casesmay exceed the boiling point of the hydrocarbon to be liquefied. I have discovered that comparatively small amounts of alcohol added to the reaction mix aid in accomplishing the desired saponification reaction at considerably reduced temperatures and in many cases particularly when the particle size of the suspension of saponification agentis sulficiently small, the reaction will even proceed at normal or but slightly raised temperature. In accordance with the invention from' .25 to 3% alcohol and preferably from .5 to 1.5% calculated reaction takes place at least until the gel formaexample:

Erample l 5% of stearic acid or rosin are dissolved in a petroleum hydrocarbon cut of a boiling range oi 145 to 210 F. 1.3% of sodium methylate (calculated as'crystal alcohol free) preferably produced by evaporating to dryness a mixture of equal parts by weight of substantially anhydrous sodium hydroxide in anhydrous methyl alcohol was thereupon added. to the smaric acid or rosin containing hydrocarbon solution. .9% oi; methyl alcohol was added to the solution. The sodium methylate was added to the solution in finely pulverized form and n'ept in fine suspension therein by means of agitation. Pulverization was carried out mechanically in a molten. In the case of the stearic acid solution, reaction proceeded al= most at once and without the necessity of raising the temperature. in the case of the rosin solution, the temperature was raised and maintained at approximately cc C. In either case agitation and in the case of resin additionally the temperature were maintained until the gel formation had proceeded to a point at which the mix was sufiiciently viscous to substantially prevent segregation of particles or saponiiication agent. The reaction mass was then poured into fuel containers in which it solidified without any further manipulation. solidification proceeded very rapidly, being substantially accomplished in both cases within a period of approximately twenty minutes.

In a further example, the same procedure was followed as hereinbefore outlined, using a rosin solution. In this-case, however, the saponiflcation agent was dispersed by means of a ball mill whereby the resulting particle size of the methylate suspension was such that saponification reaction upon the addition of 0.5% alcohol proceeded at normal temperature.

For practical purposes the alcohol addition may be effected byway of a portion of the hydrocarbon solution. Thus, for instance, a portion of the hydrocarbon to be solidified is admixed with the alcohol while another portion is prepared containlng the reaction products as, for instance, a suitable aliphatic acid or rosin and finely dispersed saponification agent. It is then only necessary to intermix both these hydrocarbon products to procure solidification. This, as is well understood, ofiers certain advantages for inductiial production.

The organic compound in accordance with my invention is preferably an aliphatic acid carrying at least one carboxyl group in aliphatic chain linkage, or preferably at least 12 carbon atoms in said chain. Aliphatic acids useful in accordance with the invention are, for instance, stearlc acid, oleic acid, palmitic acid, abietic acid, and the like. In many instances the commercial forms of these acids may be used, such as, for

instance, rosin or the products obtained by the assault splitting of fats and containing a mixture oi palmltic, stearic and oleic acids in varying proportions.- Commercial products of this type are, for instance, coconut oil fatty acids, peanut oil fatty acids, palm oil fatty acids. and the like. For best results I have found it of advantage and prefer to use rosin or stearic acid or a mixture thereof.

"The saponiilcation agent in accordance with my invention may be any agent capable of neutraliring the aliphatic acid present in the hydrocarbon solution. Good results are preferably obtained with hydroxides and alcoholateg and (ill suitable saponiiication agents of this type are.

for example, sodium hydroxide, sodium alcoholates, and the like.

in some cases I prefer to suspend thesaponification agent in substantially anhydrous pulverulent finely dispersed form in the solution containing theorganic acid with the use oi a. colloid mill or other device for procuring finest dispersion. This may be accomplished by either dispersing the dry sapo'niiicaticn agent as such in the hydrocarbon solution of the organic acid or by first preparing a fine dispersion of such saponification agent in substantially dry form in a part of the total hydrocarbon ultimately to be solidified and adding such dispersion to the other part of such hydrocarbon in which the organic acid has been dissolved. It isalso sometimes of advantage and desirable to initiate or expedite the saponification reaction by passing the reaction mix through a colloid mill or other device for procuring; finest dispersion. duch dispersion device may be also of advantageto procure finest dispersion in the case where a preliminary dispersion of the saponifioetion agent in a hydrocarbon solution is used.

When using alcoholates they are preferabl" the metal salts of monohydric and polyhydric icohols carrying the hydroxy group in alipl atic chain linkage. Examples of such alcohols are, for instance, the simple alcohols of the aliphatic series, such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, and the like alcohols. Examples of suitable polyhydric alcohols are, 'for instance, the glycols. The alcoholate formation may be accomplished by the dissolution of a suitable metal such as metallic sodium in the alcoho Whenever possible, however, such as in the case of simple aliphatic alcohols as, for instance, methyl alcohol, ethyl alcohol, and the like, I prefor to obtain alcoholate formation by addin to a strong and concentrated alcohol, a suitable solid anhydrous metal hydroxide, such as sodium hydroxide, with subsequent evaporation of excess alcohol. When proceeding in this manner I prefor to use an alcohol concentration of in excess of and preferably in excess of and preferably equimolecular proportions of alcohol and hydroxide.

The amount of reagents used within the prac tical application of my invention should be preferably so adjusted that the organic compound and the hydrocarbon are present in the hydrocarbon solution in an amount sufllcient to solidify sub stantially all of the hydrocarbon present with the soap gel formed. As a general rule, 4 to 10% in the aggregate of aliphatic acid and rosin will accomplish this result. The saponiflcationagent should be present in amount sufficient to accomplish the saponiflcation, which as a rule requires in excessof stoichiometric amounts. when using alcoholates containing crystal alcohol, care should be taken that the alcohol content is considered tion.

assume in calculating the required amount of seponification agent.

In the majority of cases the amount or alcohol introduced as crystal alcohol when using alcoholates is sufficient to expedite the saponiiication reaction to the desired extent. in some cases, however, it may be desirable to have a relatively small amount of free alcohol, i. e., alcohol not present in bound form, such as crystal alcohol; so as to at least initiate the saponification reaction whereby then further amounts of alcohol are liberated from the alcoholate to serve this purpose. In all cases, however, care should be taken that the total amount of free alcohol ultimately present in the solidified product upon completion of the saponification reaction is not substantially in excess of 3% based on the hydrocarbon. This is critical in view of the fact that higher percentage contents of alcohol may impair the characteristics of the finished solidified product, as such excess alcohol content may result in a liquefication or partial liquefication of the product upon heating or when burning. The amount of alcohol present in accordance with the invention, i. e., not appreciably in excess of about 3%, is at no time suiiicient to interfere with the effective formation of insoluble soap gel and thus solidification of the hydrocarbon material.

The alcohol to be used in accordance with the invention for expediting the saponification re-, action or bringing the same to the desired completion is preferably a primary aliphatic alcohol. The amount of this alcohol to be used may vary with the particular alcohol and depends, inter alia, upon considerations of solubility. The alcohol should be one in which the saponificstion agent is at least limitedly soluble. I prefer to use methyl or ethyl alcohol. In most cases from 0.5% to 1.5% of added alcohol will bring the saponificatiou reaction to the point of desired gel forma- In accordance with my invention and as a further embodiment thereof I find it sometimes of advantage to use a mixture of organic acids and preferably a mixture of stearic acid and rosin. The resulting stearate and resinate containin product possesses in many respects characteristics superior to those possessed by products containing the stearate of resinate alone. Inter alia, the steal-ate and resinate product has a much more uniform consistency and superior homogeneity. Furthermore, the burning characteristics are improved. Whereas, for instance, a resinate product leaves a more or less sandy residue after its combustion, the residue of the stearate containing resinate product comprises more or less compact isolated residual agglomerations.

In the practical operation of my method I find it sometimes of advantage to carry the saponification reaction only to the point of gel formation at which the desired viscosity necessary for maintaining particle suspension, prevails in the hydrocarbon mix. This may he achieved for instance by preparing a suspension of the entire amount of saponificstion agent required in the hydrocarbon solution of only a portion of the orther reaction and solidification. It is however also possible and special circumstances may make it desirable, to use in this multiple step saponification procedure an initial amount of organic compound less than that required for soap gel formation to the point of desired viscosity. In such cases, agitation should be used to insure proper suspension of saponification agent at least until the aggregate of the gel formed is sufilcient to impart to the mix the desireddegree of viscosity.

When using this procedure of successively reacting portions of organic compounds, the organic compounds for each portion may be either the same compounds or different comp unds as desired. Thus when preparing, in accordance with the invention, a solidified product containing a mixture of organic acid soaps, such as a stearate-resinate product, the particular procedure of adding the organic compounds in successive portions may be conveniently used. The

following example illustrates one mode of opera tion utilizing the two-phase saponification reaction.

Example II 800 parts by weight of naphtha containing dissolved therein 1.25% by weight of stearic acid and 1.88% by weight methyl alcohol were pro-' vided with. 1.5% by weight of substantially anhydrous pulverulent sodium hydroxide dispersed in the solution. The sodium hydroxide suspension was maintained with agitation until the completion of sodium stearate gel formation. The particle size of the sodium hydroxide in suspension was such that the sodium stearate gel formed suillced to maintain the unreacted sodium hydroxide particles in suspension.- Agitation was carried out with the aid of a. ball mill which at the same time served to produce the desired fine particle size of the hydroxide. Use of the ball mill also aided in the stearate saponification reaction which took place at normal temperatures. To the substantially stable naphtha and sodium stearate mix, containing unreactecl sodium hydroxide in substantially stable suspension, 800 parts by weight of naphtha, containing dissolved therein 8.75% by weight of'rosiu, were added. Upon thoroughly mixing the two solutions. the reaction mix was left quiescent and solidification proceeded rapidly with the formation of sodium resinatc gel.

For best results, I prefer a stearate and resinate containing product containing from 5% to 20% and preferably 10% to 15% by weight of stearate calculated on the aggregate amount of metallic soap present.

The products obtained in accordance with the invention are substantially homogeneous and can be cut with a knife and handled as ordinary solids. The products will not liquefy when subject to raised temperatures and will burn without melting. The products are further characterized by the fact that the normally liquid hydrocarbon materials which they contain may be recovered in substantially unadulterated form by the application or pressure, centrifugal manipulotions, distillation or the like. Alternatively, the hydrocarbon material may be recovered from the products solidified in accordance with the invention by separation with the aid of suitable solvent'extraction. In such case, the extracting solvent is preferably one in which the metallic soap isbut limitedly soluble or substantially insoluble. In most cases the latter type recovery oi hydrocarbon material may be procured by sloshing the solidified products, made in accordtance with the invention, with water.

The products in accordance with the invention are further characterized by a considerable density and represent essentially a substantially solid system predominantly composed of the hydrocarbon material and the metallic soap. The solidified products are substantially free from voids and have a bulk specific gravity, 1. e., specific gravity of the entire product equivalent to at least the specific gravity of the normally liquid hydrocarbon component and preferably a bull: specific gravity approximately equivalent to the total weight of the components divided by the total volume of the components. By reason of their density and characteristics of structure, the solidified products contain a high volume percentage of hydrocarbon material.

In addition to the facility with which the saponification reaction proceeds in the presence of alcohol in accordance. with the invention, a still further advantage is obtained by following this procedure. The resulting product is one of much more uniform character and of superior homogeneity and consistency with respect-to products obtained without the presence of alcohol. For this reason the use of alcohol in accordance with the invention is recommended even in those cases where the same does not aid materially the initiation or progress of the saponiilcation reaction for even in these cases the presence of alcohol during congelation will produce a superior product.

In the preparation of solidified products as hereinabove set forth the particular organic compound or acid used in the sapon'iflcation reaction may sometimes yield a product of a more or less heavy viscous molasses-like structure. This may be for instance encountered when using oleic acid. Though the resulting products are satisfactory for most purposes and will not melt but on the contrary will become increasingly more solid when heated it is as a general rule particularly for shipping and handling purposes desirable to obtain greater solidity of the compound. In most cases the lack in desired solidity can be remedied by using the particular organic compound or acid in question together with an organic compound or acid of the type yielding solidifled products of a high degree of solidity. By a proper proportioning of such organic compound or acid mixture any desired intermediate solidity can be procured. For example where oleic acid is to be used in the saponification reaction it is preferred to use a mixture of oleic acid with stearic acid or rosin.

The foregoing description is furnished by way of illustration and not of limitation and it is, therefore, my intention that the invention be limited only by the appended claims or their equivalent wherein I have endeavored to broadly all inherent novelty.

I claim:

1. Method for solidifying normally liquid inflammable hydrocarbons which comprises react ing a solution in said hydrocarbon of an organic acid of the group consisting of fatty acids and rosin acids saponifiable to produce a voluminous metallic soap gel from limitedly soluble to insoluble in said hydrocarbon, with a saponification agent of the group consisting of sodium hydrox- Ida and sodium alcoholates, suspended with agitation in said hydrocarbon in substantially dry pulverulent form, of the type reactable with said claim I acid to thereby form said soap gel, and permitting the materials to remain-substantially quiescent during at least the last stages oi. the reaction, the viscosity of the mix and the particle size oi said saponiflcation agent being so coordinated as to substantially maintain said saponification agent in suspension during at least said last stages, agitation being discontinued not earlier than the point at which said coordinated viscosity is present, the saponification being carried out in. the presence of a relatively small amount of alcohol oi the type in which said. saponiflcation agent is at least partially soluble and not appre= ciably exceeding in amount 3% by weight or" the hydrocarbon present.

, 2. Method for solidifying normally liquid inflammable hydrocarbons which comprises reactling a solution, in said hydrocarbon, oil at least one organic fatty acid, saponifiabie to produce a voluminous metallic soap gel substantially insoluble in said hydrocarbon, with a saponification agent suspended with agitation in said hydrocarbon in substantially dry pulverulent form, of the type reactable with said compound to thereby form said soap gel and comprising at least one member selected from the group consistingof sodium hydroxide and sodium alcoholates, and permitting the materials to remain substantially quiescent during at least the last stages of the reaction, the viscosity of the mix and the particle size of said saponiflcation agent being so coordinated as to substantially maintain said saponification agent in suspension during at least said last stages, agitation being discontinued not earlier than the point at which said coordinated viscosity is present, said organic acid carrying at least one carboxyl group in aliphatic chain linkage of at least twelve carbon atoms in said chain, the saponification reaction being carried out in the presence of a. relatively small. amount of alcohol of the type in which said saponification agent is at least partially soluble and not appreciably exceeding in amount 3% by weight of the hydrocarbon present.

3. Method according to claim 2 in which said organic acid is stearic acid.

l. Method ior solidifying normally liquid inflammable hydrocarbons which comprises reacting a solution, in said hydrocarbon, of at least one organic fatty acid, saponiilable to produce a voluminous metallic soap gel substantially insoluble in said hydrocarbon, with a saponification agent, suspended in said hydrocarbon in substantially dry pulverulent form, of the type reactable with said acid to thereby form said soap gel and comprising at least one member selected from the group consisting of sodium hydroxide and sodium alcoholates, agitating the mix at least until the viscosity imparted thereto by a portion oi the soap gel formed is sufllcient to maintain the saponification'agent in suspension while said mix is quiescent, discontinuing agitation and permitting the mix to remain substantially quiescent during at least the last stages of the reaction, said organic acid carrying at least one carboxyl group in aliphatic chain linkage of at least twelve carbon atoms in such chain, the saponification reaction being carried out in the presence of a relatively smallamount of alcohol 0! the type in which said saponiflcation agent is at least partially soluble and not appreciably exceeding in amount 3% by weight of the hydrocarbon present.

organic acid is stearlc acid.

6. Method for solidifying normally liquid lnflammable hydrocarbons which comprises preparing a stearic acid solution in such hydrocarbon containing alcohol not appreciably in excess of 3% by weight and an excess of saponification v agent suspended in said solution in substantially dry pulverulent form and comprising at least one member selected from the group consisting of sodium hydroxide and sodium methylate and procuring saponiflcation of said stearic acid, thereafter mixing the resulting reaction mix with a solution of rosin in such hydrocarbon and procuring the saponification of said rosin with the unreacted portion of said saponification agent, agitating the mix throughout the saponiflcation reaction at least until the viscosity imputed to the mix by a portion of soap gel formed is sument, and said alcohol being of the type in which said saponification agent is at least partially soluble.

ALBERT JOSEPH LAIJBERTE'. 

